Before you buy a new cell phone or new tablet, please try the following procedure to repair your device. First charge your battery, backup your important data if possible and in most cases take out SIM and SD card before factory reset. It is impossible to recover your data after doing a hard reset, so online backup is always important. For all of your data, a backup should be done on an external device, hard drive, raid system or media. With or without insurance, if your cell phone lost, damaged or stolen at least your invaluable data is backed up in a safe place. If you are about to sell your phone and you want to wipe your personal data, or if your phone affected with virus you have to do a hard reset. In some cases, you can delete the forgotten password or lock pattern from your device as well. All information is for devices with stock based ROMs. If you are using rooted device, always back up your EFS folder first, containing your IMEI info, etc.!
Google Nexus 10 hard reset
How to get into Nexus 10 recovery modeTurn off your Nexus 10 tablet. Press and hold Volume UP+DOWN+POWER buttons and plug in to your computer the tablet to get into the recovery mode.
Select Wipe data Factory reset and then choose yes to confirm. All data will be lost! Unlock Nexus tablet forgotten password pattern
Nexus Bootlop recovery
1. Press both Volume +/- and POWER buttons.
2. Scroll down to Recovery with the Volume down button and press power.
You should see Android with a red triangle.
3. Briefly press VOLUME UP + POWER.
4. Select factory reset/data wipe (with the volume key) and then reboot yout Nexus tablet.
or from the menu
To reset your Nexus 10 to factory settings and erase all the data on your tablet, Select Settings → Back up and reset→ Factory data reset → Reset tablet→ Delete all.
or older firmware
1. From the Home screen, press the Menu Key and touch Settings.
2 Touch the Privacy
4 Touch Factory data reset.
5 Touch Reset tablet.
6 Touch Erase everything.